Electric-arc



(N0 Modem J. J. SKINNER.

ELECTRIC ARC LAMP. No. 304,673. Patented Sept. 2, 1884.

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lUNTTED STATES PATENT Oriana,

JOSEPH J. SKINNER, OF NEYVTON, MASSACHUSETTS, ASSIGNOR TO THE THOMSON-HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

SPECIFICATION forming part of Letters Patent No. 304,673, dated$eptember 2, 1884.

A pplieation filed February 18, 1884. (No model) To all whom it mayconcern,-

Be it known that I, J osEPH J. SKINNER, of Newton, county of Middlesex,State of Massachusetts, have invented an Improvement in Electric Lamps,of which the following de scription, in connection with the accompanyingdrawing, is a specification, like letters on the drawing representinglike parts.

My invention relates to an electric lamp of that class in which thecarbons are controlled by a single magnet included in ashunt-circuitaround the carbons and are.

The present invention consists, essentially, in the combination, wit-hthe controlling-magnet placed in a shuntcircuit, of appliances wherebythe said magnet is energized when the carbons are in contact, and whilethe arc-resistance is small, the said magnet operating by its continuedattraction to first separate the carbons and establish the arc, andsubsequently to produce the feed of the carbon, when the strength of thesaid magnet is still further increased by the lengthening of the are dueto the consumption of the carbons. The lamp is provided with resistance,which, before the current begins to flow, is included in the maincircuit through the carbons, and thus causes a sufiicient portion of thecurrent to pass through the shunt-magnet to energize the latter, thearmature of which is connected with the usual clamp orcarbon-controlling device in such a manner that the said armature in itsmovement caused by the attraction of its magnet will lift the uppercarbon, thus establishing the are, which, by its resistance, tends tostill further strengthen the said magnet. The armature also operates acircuit controller or switch, which removes the resistancefrom the maincircuit, preferably gradually in proportion as the arc is lengthened, sothat the resistance of the arc takes the place of that removed from thecircuit.

The drawing shows in front elevation an electric lamp embodying thisinvention, the front plate of the lamp box or frame being removed.

The lamp-box a, upper carbon or carbon holding rod, 12, and the clamp c,or carbon-controlling device may be of any suitable or usualconstruction, the said clamp being shown in this instance as connectedwith one end of a toggle-jointed or elbow-lever, d d, the other end ofwhich is pivoted on an arm, 6, fixed with relation to the lamp-box. Thejoint of the lever d d is connected by a link, f, with the armature orcores 9 of the controlling magnet or solenoid h of the lamp in such aman ner that by the continuous movement of the said armature toward'itsmagnet, the togglelever is first straightened, separating its ends andraising the upper end, and connected clamp c, after which by the furthermovement of the armature, the lever is again bent, causing its ends tobe drawn together, or the clamp 0 connected with the movable end to belowered, so that the arm 0 of the clampjaw 0 will ultimately be broughtagainst the stop or tripping projection 0 causing the jaw to relax itspressure on the carbon-rod and permitting the latter to feed by gravityin the usual manner.

,The magnet 71, is included in a shunt or derived circuit, 2 3, from themain circuit entering the lamp at the binding-post 4, andleaving it atthe binding-post 5, the said main circuit being continued by wire 6 to acircuit-controlling device, i, operatively connected with the armature gof the magnet h. The main circuit is continued from thecircuit-controlling device or contact-spring ithrough a greater or lessportion of the resistance It to the wire 7, connected by a suitablecontact spring or brush, on, with the upper carbon, from which the maincircuit is continued to the lower carbon, b, and thence by wire 8 to thebindingpost 5. with a series of contacts connected with the differentportions of the resistance in such manner that when the armature g iswholly retracted, as before the current begins to flow, the whole or thegreater portion of the said resistance It will be in the main circuit,so that, although the carbons are in contact and offer but littleresistance, nevertheless a considerable portion of the current will becaused to pass through the shunt 2 3 and magnet h, energizing thelatter, so that it attracts its armature 9, thus straightening thetoggle-lever, raising the carbon, and establishing the are. As soon asthe carbons are separated the are itself will offer sufficientresistance to cause the magnet h to be energized the necessary amount,

The spring 13 preferably co-operates and consequently the resistance 7.:may be removed from the main circuit, and the magnet h will then beaffected by the variations in re sistance of the are alone in the usualmanner.

The circuit-controlling device '5 and its to operating contact-pointsare preferably so arranged that in the movement of the armature by whichthe lever is straightened the resistance 70 will be gradually removedfrom the circuit, the portion removed being replaced by the preferablysomewhat greater resistance of the increasing are, and by the time thatthe lever is straightened so that the clamp is raised to its highestpoint the said resistance 70 will preferably be wholly removed. Then asthe carbon b urns away, inereasin g the length of the arc, theattractive strength of the magnet h is proportionately increased, movingthe joint of the toggle-lever beyond the central line, and thus drawingthe ends of the lever together and gradually depressing the clamp, thustending to move the carbon downward to compensate for its consumption,until finally the clamp is moved down to the point at which the arm 0 isengaged and the pressure of the clamp-jaw relaxed by the trippingprojection 0", thus permitting the carbon to slip and feed in the usualmanner.

The armature g has a suitable retractor, (shown as a spring, y,) and thebracket 0" serves as a stop to limit the movement of the armature awayfrom its magnet.

In other lamps with which I am acquainted, in which an initialresistance causes the energizing of a shunt-magnet, which subsequentlygoverns the feeding of the carbons, this initial resistance is removedbefore the establishment of the are, and the latter operation isaccomplished by a retractor acting in opposition to the shunt-magnet,while in the present invention the initial resistance is removed duringor after the establishment of the are, and the are is established by thedirect pull of the shunt-magnet.

llhe mechanical. devices which I have our ployed in carrying out thepresent invention are substantially the same as those shown anddescribed in Letters Patent to IE. Thomson, No. 274,413, dated March 20,1888.

I claim- 1. The carbon-controlling device or clamp and thecontrollinganagnet, in a shunt around the carbons,and the armature ofthe said magnet, combined with the actuating mechanism for the saidclamp connected with the said armature, and adapted to produce in thec011- tinuous movement of the armature in one direetion a movement ofthe clamp first in one and then in the opposite direction, andresistance controlled by the said armature,whereby the magnet is causedto be energized before and during the establishment of the are,substantially as described.

2. The controlling-magnet in a shunt around the carbons,and the clampconnected with the armature of the said magnet,and operated by theattraction thereof to establish the arc,eombined with resistance,and acircuit-controlling device therefor operatively connected with the saidarmature, whereby the said resistance is included in circuit with thecarbons when the armature is rctracted,and removed by the movement ofthe said armature when attracted to establish the are,substantially asdescribed.

3. The clamp and controlling magnet in a shunt around the carbons,and anarmature and a toggle-lever connected with the said clamp and armature,combined with resistance, and a circuitcontrolling device therefor,operated by the said armature to place the said resistance in circuitwith the carbons when the armature is ret acted, and remove it therefromwhen the magnet is energized to establish the are, substantially asdescribed.

at. In an electric lamp, a controlling magnet in a shunt-circuit aroundthe carbons, and a carbon-cl amp operated by the attraction of the saidmagnet to establish the are, combined with resistance included in thecircuit of the carbons while the latter are in contact, and acontrolling device for said resistance operated by the saidcontrolling-magnet, whereby the said resistance is gradually removedfrom the circuit of the carbons as the latter are separated and thearc-resistance produced, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JOSEPH J. SKINNER.

Witnesses:

Jos. P. Livnnm'oiu-l, W. H. SI'GSTO'N.

